The ultimate lines and their exciting potentials - Clasification and exciting potentials. The ultimate lines are classified as primary, secondary or tertiary as suggested by Russel, modifying the nomeclature, in the form proposed by Catalan and by us. The following table give the number of ultimate lines for the different classes and the minimum and maximum values uf their exciting potentia. Those computational data are based on the table of the author published in Twyman and Smiths Book.